JP4645870B2

JP4645870B2 - Sewing detachment detection device

Info

Publication number: JP4645870B2
Application number: JP2000282666A
Authority: JP
Inventors: 貴義正岡
Original assignee: Yamato Sewing Machine Mfg Co Ltd
Current assignee: Yamato Sewing Machine Mfg Co Ltd
Priority date: 2000-08-14
Filing date: 2000-08-14
Publication date: 2011-03-09
Anticipated expiration: 2020-08-14
Also published as: TW550320B; CN1338535A; CN1194127C; JP2002058889A

Description

【０００１】
【発明の属する技術分野】
本発明は、主としてオーバーロックミシンによる縁かがり縫い縫製時において上下に重ね合わせられた２枚の被縫製生地のうち、少なくとも一方の生地の端縁部が所定の縫製位置から外れたか否かを光学的に検出し縫製作業者に報知するなどして縫製不良品の発生を防止するように用いられるミシンの縫外れ検出装置に関するものである。
【０００２】
【従来の技術】
オーバーロックミシンによって上下に重ね合わせられた縫製生地の縁かがり縫いなどの縫製を行う場合、特に、下生地は縫製作業者が見づらくて縫製途中での位置修正が非常に難しいために、その端縁部が縫製進行方向と直交する生地幅方向に位置ずれして所定の縫製位置（縫目）から外れてしまう、いわゆる縫外れを発生しやすい。このような縫外れは縫製品にとって致命的な欠陥である。
【０００３】
このような縫外れを光学的に検出して縫製不良品の発生を防止する装置として従来、例えば実公昭５９−２５３４９号公報などに開示されているように、光透過式の光電センサを用いて縫外れを検出するように構成されたものが知られている。上記公報などに開示されている従来の縫外れ検出装置は、縫製生地に対して光線を投光する投光器と該投光器に対応させて縫製生地を透過した光線を受光する受光器とからなる光透過式光電センサを用い、縫製生地の重なり枚数、つまり、上生地と下生地とが重なっているか否かによって変化する透過光量の増減を検出することによって縫外れを検出するように構成されたものである。
【０００４】
【発明が解決しようとする課題】
しかしながら、光透過式光電センサを用いた従来の縫外れ検出装置の場合は、透過光量の増減により縫外れの有無を検知するものであるから、厚みや光透過特性が異なる縫製生地の種類の変更の度に、光電センサの感度調整（補正）といった面倒かつ手間のかかる作業を行う必要があり、少量多品種の生地の縫製に用いられるミシンの縫外れ検出装置としては実用性に欠けるという問題があった。
【０００５】
本発明は上記の実情に鑑みてなされたもので、厚みや光透過特性が異なるいかなる種類の生地を縫製する場合でも、面倒な感度調整作業を要することなく、縫外れの発生を確実かつ正確に検出することができるミシンの縫外れ検出装置を提供することを目的としている。
【０００６】
【課題を解決するための手段】
上記目的を達成するために、本発明に係るミシンの縫外れ検出装置は、針板における針落ち部の近傍位置に設置されて、上下に重ね合わせられた縫製生地の端縁部が所定の縫製位置から外れたか否かを光学的に検出するように構成されているミシンの縫外れ検出装置であって、縫製生地の端縁を切揃え切断するメス機構よりも縫製進行方向の手前位置の針板の上方及び下方位置のそれぞれに、上生地の端縁部及び下生地の端縁部の有無を個別に検知する反射式光電センサが設けられているとともに、これら上下の光電センサからの投光光線をそれぞれ上方及び下方に向けて反射させる反射部が設けられ、かつ、上下の反射式光電センサによる両検知信号を処理して縫製生地の縫外れの有無を判定し、その判定結果を受けて動作する検出手段が設けられ、さらに、上下の反射式光電センサのうち、下側の光電センサは、メス機構の下メス台に支持されており、縫製進行方向に直交する方向へのメス機構の移動に伴う切揃え切断位置の調整に合わせて上下の反射式光電センサの位置を調整するに当たり、下側の光電センサは切揃え切断位置の調整のための下メス台の移動に伴い該下メス台と一体に位置調整可能に構成されていることを特徴とするものである。
【０００７】
上記構成の本発明によれば、針板の上方及び下方位置にそれぞれ各別に設けられた反射式光電センサにより、上下に重ね合わせられている上生地及び下生地の端縁部の有無が個別に検知され、それら両検知信号の信号処理によって縫製生地の縫外れの有無が判定され、その判定結果に基づいて検出手段が動作するものであるから、縫製生地の厚み（厚薄）や生地固有の光透過特性が異なるいかなる種類の生地を縫製する場合も、面倒な光電センサの感度調整を行うことなく、上生地及び下生地のいずれか一方でも、その端縁部が所定の縫製位置から外れている縫外れを確実かつ正確に検出することが可能である。
【０００８】
また、上下の反射式光電センサを、縫製生地の端縁を切揃え切断するメス機構よりも縫製進行方向の手前位置に設け、これら上下の反射式光電センサの位置を縫製進行方向に直交する方向へのメス機構の移動に伴う切揃え切断位置の調整に合わせて調整可能に構成することにより、メス機構の移動によるかがり幅の調整に伴って上下両光電センサをメス機構の切揃え切断位置に対応する所定の検知位置に位置調整することが可能であり、かがり幅の調整にかかわらず、所定の縫外れ検出機能を確実に保持することができる。
【０００９】
その上、光電センサの位置調整のための構成として、下側の光電センサをメス機構の下メス台に支持させ、切揃え切断位置の調整のための下メス台の移動に伴い下側の光電センサを下メス台と一体に位置調整可能に構成することによって、かがり幅調整のために当然に行われる下メス台の移動量と下側の光電センサの位置調整量とを完全に一致させることが可能で、かがり幅の調整後に、下側の光電センサの位置を別途に調整する必要がなくなり、所定の縫外れ検出機能を確保したままでのかがり幅変更を容易かつ迅速に行うことができる。
なお、上側の光電センサは、下メス台の移動に伴い一体に位置調整された下側の光電センサからの投光光線を照準にして位置調整することで、かがり幅調整後の所定の検知位置に容易かつ正確に調整することができる。
【００１０】
また、上記構成のミシンの縫外れ検出装置において、上下の光電センサからの投光光線をそれぞれ上方及び下方に向けて反射させる反射部を、請求項２に記載のように、上下の生地間に介在されて上下生地の縫製進行方向への移動を案内する縫製生地案内部材の上下面にそれぞれ形成する構成を採用することによって、薄い生地であっても、上下の生地を案内部材に沿わせて弛み等の生じないように移動案内しつつ、上方及び下方への投光光線の反射作用を確実にして上下両光電センサによる生地端縁部の有無の検知性能を高めることができる。
【００１１】
上記のような上下反射面付き案内部材を備えたミシンの縫外れ検出装置において、請求項３に記載のように、案内部材を縫製生地案内作用位置と針板から離間した非案内作用位置との間に亘り位置変更自在に構成することにより、縫製対象物が筒状縫製物である場合でも、案内部材が所定の縫製の妨げになったり、縫製後の縫製物の取り出しの邪魔になったりすることがない。すなわち、筒状縫製物の縫製が進行してその縫い始め端部が針落ち部手前にきたとき、案内部材を非案内作用位置に位置変更（退避）させることにより、縫い始め端部が案内部材に引っ掛かることなく、縫い終わり端部まで確実に縫製することができるとともに、縫製後の筒状縫製物を案内部材に邪魔されることなく縫製箇所から取り出すことができる。
【００１２】
さらに、上記構成のミシンの縫外れ検出装置において、請求項４に記載のように、上下の光電センサとして、その投光・受光素子の前面にそれぞれ偏光フィルタを有し、投光側では偏光フィルタを通過させて横方向もしくは縦方向の波の光線のみを投光し、かつ、受光側では偏光フィルタを通過させて縦方向もしくは横方向の波の反射光線のみを受光する回帰反射型の光電センサを使用するとともに、これら上下の光電センサからの投光光線を上方及び下方に向けて反射させる上記反射部の反射面として、投光される横方向もしくは縦方向の波のみの光線をあらゆる方向の波の光線に偏光して反射させる機能を持つ回帰反射テープを使用することによって、投光位置に光沢のある物体や部位が存在したり、生地そのものが光反射性の強いものであっても、それらからの反射光（外乱光）と反射テープからの反射光とを明確に区別することが可能であり、これによって、上下光電センサが上下生地の端縁部の有無のみを正確に検知し、誤検知、誤検出動作がなくなり、所定の縫外れ検出精度を著しく高めることができる。
【００１３】
【発明の実施の形態】
以下、本発明の実施の形態を図面にもとづいて説明する。
図１は本発明に係る縫外れ検出装置を備えたオーバーロックミシンＭの要部の概略斜視図、図２は同ミシンＭの要部の平面図である。このオーバーロックミシンＭのクロスプレート１には、その上面がクロスプレート１の上面と面一になる状態で針板２が固定されている。この針板２の下部で、かつ、ミシンフレーム３に上下往復運動自在に支持された針棒４の下端部に針止め５を介して取り付けられているミシン針（図示省略する）の針落ち部６を挟んだ前後位置には、上下に重なり合わせられた縫製生地Ｗを矢印Ｙで示す縫製進行方向に送る前・後の送り歯（周知であるため、図示は省略する）が配設されているとともに、上記針板２の上部には被縫製生地Ｗを該針板２上面に押圧する押え金７が押え腕８を介して上下動可能に設けられており、送り歯によって縫製生地Ｗを縫製進行方向Ｙに送りながら、ミシン針と図示省略したルーパとの協働作用により縁かがり縫いを行うように構成されている。
【００１４】
上記針板２における針落ち部６よりも縫製進行方向Ｙの手前位置には、クロスプレート１及び針板２の上面に沿い針落ち部６に向けて縫製進行方向Ｙに送られる縫製生地Ｗの端縁Ｗｅを切揃え切断するためのメス機構９が設置されている。このメス機構９は、平板状の上メス９Ａと帯板状の下メス９Ｂとを備えており、該メス機構９の縫製進行方向Ｙと直交するＸ１−Ｘ２方向への移動により切揃え切断位置、つまり、かがり幅が調整可能に構成されている。このメス機構９の具体的な構成及びかがり幅の調整構造は次のとおりである。
【００１５】
即ち、図５に明示するように、オーバーロックミシンの主軸（周知のため、図示省略）に連動された上メス軸１０に固定されて揺動する上メス軸腕１１にＬ字形状の上メスホルダー１２が止ネジ１３及び長孔１４を介して矢印Ｘ１−Ｘ２方向に移動固定自在に取り付けられており、この上メスホルダー１２の側面に押当ててボルト１５及び長孔１６を介して上下に位置調整可能な状態で平板状の上メス９Ａが取り付けられている。
【００１６】
一方、クロスプレート１の下部に配置し固定された下メス台取付台１７には、この取付台１７に内蔵のバネ１８を介して縫製進行方向Ｙに対して直交するＸ１−Ｘ２方向で上メス９Ａ側に弾性付勢させる状態で下メス台１９が支持されており、この下メス台１９に下メス押え２０及び止ネジ２１を介して帯板状の下メス９Ｂが固定保持されているとともに、下メス台１９をバネ１８の弾性付勢力に抗して下メス取付台１７に締付け固定可能な止ネジ２２が設けられている。なお、図５中の２３は下メス台１９の回り止め部材で、止ネジ２４を介して下メス取付台１７に固定されている。
【００１７】
上記のごとき構成のメス機構９においては、止ネジ１３を緩めて上メスホルダー１２及び上メス９Ａを長孔１４に沿い縫製進行方向Ｙと直交するＸ１−Ｘ２方向に必要量だけ移動させ固定させると共に、止ネジ２２を緩めて下メス台１９及び下メス９Ｂをバネ１８の付勢力によって、あるいは、バネ１８の付勢力に抗して上記と同じＸ１−Ｘ２方向に移動させて上下両メス９Ａ，９Ｂを弾性的に密着させることにより、かがり幅を調整可能としている。
【００１８】
上記のようなメス機構９よりも縫製進行方向Ｙの手前位置の針板２の上方及び下方位置のそれぞれには、図３、図４にも明示するように、上生地Ｗｕ及び下生地Ｗｄに向けてそれぞれ投光される光線の反射光を受光したか否かによって上生地Ｗｕ及び下生地Ｗｄの端縁部の有無を個別に検知する反射式光電センサ２５及び２６が設けられている。これら上下の反射式光電センサ２５，２６のうち、下側の光電センサ２６としては、上述したメス機構９の下メス台１９等のメス機構用部品が存在して取り付けスペースに余裕がないために、ファイバーセンサを使用している。
【００１９】
上側の反射式光電センサ２５は、図１に示されているように、センサ取付腕板２７に形成されている長孔２８とそれに嵌合するボルト２９を介して縫製進行方向Ｙと直交するＸ１−Ｘ２方向に移動固定自在な状態でミシンフレーム３に取り付けられており、上記メス機構９の切揃え切断位置（かがり幅）の調整に合わせてセンシング位置が調整可能に構成されている。
【００２０】
一方、ファイバーセンサからなる下側の光電センサ２６は、図２〜図４に示されているように、ファイバー支え３０及びファイバー押え３１を介してメス機構９における下メス台１９に固定支持されており、上述したかがり幅調整のための下メス台１９のＸ１−Ｘ２方向への移動に伴い、下メス９Ｂ及び下メス台１９と一体にセンシング位置調整可能に構成されている。なお、下側の光電センサ２６の検出端２６ａが臨む針板２部分には、かがり幅調整のために光電センサ２６が下メス台１９と一体にＸ１−Ｘ２方向のいずれの箇所に移動した場合でも、下生地Ｗｄに対する所定のセンシング機能が保てるようにするための長孔状のガイド溝３２が形成されている。
【００２１】
また、上生地Ｗｕと下生地Ｗｄの間には、それら上、下生地Ｗｕ，Ｗｄの縫製進行方向Ｙへの移動を案内する板状の縫製生地案内部材３３が介在されており、この案内部材３３の上下面にそれぞれ回帰反射テープ３４，３５を接着して上下の光電センサ２５，２６からの投光光線を上方及び下方に向けて反射させる反射面（反射部）が形成されている。
【００２２】
この上下反射テープ３４，３５付きの案内部材３３は、ミシンフレーム３に取付板３６及び土台３７を介して固定支持された伸縮（進退）シリンダ３８の可動ロッド３８ａ先端部に固定されており、シリンダ３８の伸縮動作によって、その先端が針板２上に延出された縫製生地案内作用位置と針板２から離間した非案内作用位置との間に亘り位置変更自在に構成されている。
【００２３】
図６は上記上下の反射式光電センサ２５，２６を含む縫外れ検出装置の回路構成を示すブロック図であり、上下の各光電センサ２５，２６による検知信号Ｓ１，Ｓ２は増幅器４０，４１で増幅されたのち、制御部４２に入力される。この制御部４２には、検知信号Ｓ１，Ｓ２のほかに、オーバーロックミシンＭの例えば主軸（図示省略する）に取り付けられて回転の有無を検出する回転検出器４４からの検知信号Ｓ３及び縫製進行方向Ｙに沿って一定長さ範囲の許容縫外れ量としての運針数を予め作業者によって数値入力する許容縫外れ設定器４３からの許容縫外れ量（運針数）設定信号Ｓ４がそれぞれ入力されており、該制御部４２は上下両光電センサ２５，２６による検知信号Ｓ１，Ｓ２のうちのいずれか一方の信号の入力継続時間に相当する運針数と設定信号Ｓ４の許容運針数とを比較して、検出運針数が許容運針数を越えたとき、縫外れ有りと判定して信号Ｓ５を出力する。
【００２４】
上記制御部４２には、ランプ、ブザーまたは表示画面の少なくとも一つからなる縫外れ報知手段４５が接続されており、上記制御部４２からの出力信号Ｓ５を受けて点灯、鳴動または表示動作して作業者に縫外れが発生したことを知らせるように構成されている。なお、上記許容縫外れ量は運針数の設定により任意に可変であるが、この運針数に代えて、上記両光電センサ２５，２６による検知信号Ｓ１，Ｓ２のうちのいずれか一方が制御部４２に入力された時点から動作開始されるタイマーを用い、このタイマーの動作限時時間の設定により許容縫外れ量を可変としてもよい。
【００２５】
次に、上記のような構成の縫外れ検出装置を備えたオーバーロックミシンＭを用いて、例えばＴシャツの袖付け縫製等を行なう際の縫外れ検出動作について、図７のフローチャート及び図８（Ａ），（Ｂ）の作用図を参照して簡単に説明する。
【００２６】
Ｔシャツの袖用生地と身頃用生地などのように、上生地Ｗｕと下生地Ｗｄとが上下に重ね合わせられた縫製生地Ｗは前・後の送り歯によってクロスプレート１及び針板２の上面に沿って縫製進行方向Ｙに送られ、針落ち部６の手前位置でメス機構９によりその端縁Ｗｅが切揃え切断された後、針落ち部６に送られてミシン針と図示省略したルーパとの協働作用により縁かがり縫いが行われる。
【００２７】
上記のような縁かがり縫製時には、上下反射テープ３４，３５付きの案内部材３３がシリンダ３８を介してその先端を針板２上に延出させた縫製生地案内作用位置に位置されており、縫製生地Ｗが薄いものであっても、上下生地Ｗｕ，Ｗｄを案内部材３３に沿って弛み等の生じないように移動案内する。そして、メス機構９よりも手前の位置で縫製生地Ｗの上生地Ｗｕ及び下生地Ｗｄの端縁部には上下の反射式光電センサ２５，２６からパルス状の光線が投光され、その反射光を受光するか否かによって上下生地Ｗｕ，Ｗｄの端縁部の有無を検知している（ステップＳ１１，Ｓ１２）。
【００２８】
ここで、上生地Ｗｕ及び下生地Ｗｄの端縁部が共に、図８（Ａ）のように、投光光線よりも右側にはみ出している状態では上下の光電センサ２５，２６が反射光を受光せず、これら光電センサ２５，２６から制御部４２には生地端縁部有りの検知信号Ｓ１，Ｓ２が入力されるため、これら生地端縁部有りの検知信号Ｓ１，Ｓ２が入力される制御部４２では、それら検知信号Ｓ１，Ｓ２の信号処理によって縫外れ無しと判定され（ステップＳ１３）、次のステップに移行することなく、そのまま所定の縁かがり縫製が続行される。
【００２９】
一方、図８（Ｂ）のように、上生地Ｗｕ及び下生地Ｗｄのうち、いずれか一方の端縁部、例えば上生地Ｗｕの端縁部が投光光線よりも左側にずれている状態では、上側の光電センサ２５からの投光光線が案内部材３３の上面に接着されている反射テープ３４から上方へ向けて反射され、その反射光を上側の光電センサ２５が受光して、この上側の光電センサ２５から制御部４２には生地端縁部無しの検知信号Ｓ１が、また、下側の光電センサ２６から制御部４２には生地端縁部有りの検知信号Ｓ２が入力され、それら検知信号Ｓ１，Ｓ２の信号処理によって縫外れ有りと判定される（ステップＳ１３）。
【００３０】
上記制御部４２には、作業者によって許容縫外れ設定器４３に予め数値入力されている縫製進行方向Ｙに沿う長さの許容縫外れ量としての運針数設定信号Ｓ４が入力されており、この設定信号Ｓ４の許容運針数Ｍ１と検知信号Ｓ１（またはＳ２）の入力継続時間に相当する検出運針数Ｍ２とが比較され（ステップＳ１４）、検出運針数Ｍ２が許容運針数Ｍ１よりも小さいとき、信号Ｓ５は出力されず、検出運針数Ｍ２が許容運針数Ｍ１を越えたとき、縫外れが発生したと判定して制御部４２から信号Ｓ５が出力される（ステップＳ１５）。この制御部４２からの出力信号Ｓ５が縫外れ報知手段４５に入力されることによってランプが点灯したり、ブザーが鳴動したりして作業者に縫外れの発生が報知されることになる。
【００３１】
上記のように、針板２の上方及び下方位置にそれぞれ各別に設けられた反射式光電センサ２５，２６により、上下に重ね合わせられている上生地Ｗｕ及び下生地Ｗｄの端縁部の有無を個別に検知し、それら両検知信号の信号処理によって縫製生地Ｗの縫外れの有無を判定して、その判定結果に基づいて放置手段４４を動作させることにより、縫製生地Ｗの厚み（厚薄）や生地固有の光透過特性が異なるいかなる種類の生地を縫製する場合も、光電センサ２５，２６の感度調整を行う必要がなく、上生地Ｗｕ及び下生地Ｗｄのいずれか一方でも、その端縁部が所定の縫製位置から外れている縫外れが発生したならば、それを確実かつ正確に検出することが可能である。
【００３２】
なお、本実施の形態のように、下側の光電センサ２６をメス機構９の下メス台１９に支持させ、切揃え切断位置の調整のための下メス台１９の移動に伴い下側の光電センサ２６を下メス台１９と一体にＸ１−Ｘ２方向に位置調整可能に構成することによって、かがり幅調整のために当然に行われる下メス台１９の移動量とかがり幅調整に対応して必要となる下側の光電センサ２６の位置調整量とを完全に一致させることが可能で、かがり幅の調整後に、下側の光電センサ２６の位置を別途に調整しなくても、所定の縫外れ検知機能を確保したままでのかがり幅調整を容易かつ迅速に行うことができる。ここで、上側の光電センサ２５は、下メス台１９の移動に伴い一体に位置調整された下側の光電センサ２６からの投光光線を照準にしてセンサ取付腕板２７に形成されている長孔２８とそれに嵌合するボルト２９を介して縫製進行方向Ｙと直交するＸ１−Ｘ２方向に移動固定させてセンシング位置を調整することで、かがり幅調整後の所定の検知位置に容易かつ正確に調整することができる。
【００３３】
また、案内部材３３を上述したような縫製生地案内作用位置と針板２から離間した非案内作用位置との間に亘り位置変更自在に構成することにより、縫製対象物が筒状縫製物である場合でも、その筒状縫製物の縫製が進行してその縫い始め端部が針落ち部６手前にきたとき、シリンダ３８を介して案内部材３３を非案内作用位置に位置変更（退避）させることで、縫い始め端部が案内部材３３に引っ掛かることなく、縫い終わり端部まで確実に縫製することができるとともに、縫製後の筒状縫製物を案内部材３３に邪魔されることなく縫製箇所から容易に取り出すことができる。
【００３４】
さらに、上下の光電センサ２５，２６として、その投光・受光素子の前面にそれぞれ偏光フィルタ（図示省略する）を有し、投光側では偏光フィルタを通過させて横方向（もしくは縦方向）の波の光線のみを投光し、かつ、受光側では偏光フィルタを通過させて縦方向（もしくは横方向）の波の反射光線のみを受光する回帰反射型の光電センサを使用するとともに、これら上下の光電センサ２５，２６からの投光光線を上方及び下方に向けて反射させるための回帰反射テープ３４，３５として、投光される横方向（もしくは縦方向）の波のみの光線をあらゆる方向の波の光線に偏光して反射させる機能を持つ回帰反射テープを使用することによって、投光位置に光沢のある物体や部位が存在したり、縫製生地Ｗそのものが光反射性の強いものであっても、それらからの反射光（外乱光）と反射テープ３４，３５からの反射光とを明確に区別することが可能であり、これによって、上下光電センサ２５，２６は上下生地Ｗｕ，Ｗｄの端縁部の有無のみを正確に検知し、誤検知、誤検出動作がなくなり、所定の縫外れ検出精度を著しく高めることができる。
【００３５】
なお、本発明における反射部としては、上記した偏光機能を有する回帰反射テープ３４，３５により形成することが最も好ましいが、そのような偏光機能のない反射テープを用いても、また、案内部材３３の上下面を鏡面加工して反射面を形成してもよい。
【００３６】
また、本発明は、基本的に縫外れがあったことを作業者が認識することで縫製不良品の発生を防げればよいものであるから、ランプやブザー、表示画面などの報知手段４４を設けたものについて説明したが、このほかに、縫外れ検出に伴ってミシンＭの作動を自動停止するような構成を付加してもよい。
【００３７】
【発明の効果】
以上のように、本発明によれば、上下に重ね合わせられている上生地及び下生地の端縁部の有無を個別に検知し、それら両検知信号の信号処理によって縫製生地の縫外れの有無を判定し、その判定結果に基づいて検出手段を動作させるようにしたので、縫製生地の厚み（厚薄）や生地固有の光透過特性が異なるいかなる種類の生地を縫製する場合も、面倒な光電センサの感度調整を行う必要がなく、上生地及び下生地のいずれか一方の端縁部が所定の縫製位置から外れているような縫外れの発生を確実かつ正確に検出することができるという効果を奏する。
【００３８】
また、メス機構の移動によるかがり幅の調整に伴って上下両光電センサをメス機構の切揃え切断位置に対応する所定の検知位置に位置調整することが可能であり、かがり幅の調整にかかわらず、所定の縫外れ検出機能を確実に保持することができる。
【００３９】
その上、かがり幅調整のために当然に行われる下メス台の移動量と下側の光電センサの位置調整量とを完全に一致させることが可能で、かがり幅の調整後に、下側の光電センサの位置を別途に調整する手間を要することなく、所定の縫外れ検出機能を確保したままでのかがり幅調整を容易かつ迅速に行うことができる。
【００４０】
また、請求項２に記載の発明によれば、上記効果に加えて、薄い生地であっても、上下の生地を案内部材に沿わせて弛み等の生じないように移動案内しつつ、上方及び下方への投光光線の反射作用を確実にして上下両光電センサによる生地端縁部の有無の検知性能を高めることができる。
【００４１】
さらに、請求項３に記載の発明によれば、上記効果に加えて、筒状縫製物であっても、案内部材が所定の縫製の妨げになったり、縫製後の縫製物の取り出しの邪魔になったりすることがなく、当該縫外れ検出装置を筒状縫製物にも有効に適用することができる。
【００４２】
さらにまた、請求項４に記載の発明によれば、外乱光と正規の反射光とを明確に区別することが可能であり、これによって、誤検知、誤検出動作をなくして、所定の縫外れ検出精度を著しく高めることができる。
【図面の簡単な説明】
【図１】本発明に係る縫外れ検出装置を備えたオーバーロックミシンの要部の概略斜視図である。
【図２】同上ミシンの要部の平面図である。
【図３】同上ミシンの要部の正面図である。
【図４】同上ミシンの要部の右側面図である。
【図５】同上ミシンにおけるメス機構の詳細構成を示す要部の分解斜視図である。
【図６】上下の反射式光電センサを含む縫外れ検出装置の回路構成を示すブロック図である。
【図７】かがり縫い時における縫外れ検出動作を説明するフローチャートである。
【図８】（Ａ），（Ｂ）はかがり縫い時における上下生地の端縁部の検知状況を説明する概略側面図である。
【符号の説明】
２針板
６針落ち部
９メス機構
９Ａ上メス
９Ｂ下メス
１９下メス台
２５，２６反射式光電センサ
３３縫製生地案内部材
３４，３５回帰反射テープ
４５縫外れ報知手段
Ｍオーバーロックミシン
Ｗ縫製生地
Ｗｕ上生地
Ｗｄ下生地
Ｓ１，Ｓ２光電センサによる検知信号
Ｙ縫製進行方向
Ｘ１−Ｘ２かがり幅調整方向[0001]
BACKGROUND OF THE INVENTION
The present invention optically determines whether or not the edge of at least one of the two fabrics to be sewn up and down at the time of edge overlock sewing mainly by an overlock sewing machine has deviated from a predetermined sewing position. The present invention relates to a sewing-off detection device for a sewing machine that is used so as to prevent the occurrence of defective sewing products by, for example, automatically detecting and informing a sewing manufacturer.
[0002]
[Prior art]
When performing sewing such as over-the-edge stitching of the sewing fabric that is overlaid by the overlock sewing machine, the edge of the lower fabric is particularly difficult to adjust because it is difficult for the sewing manufacturer to see. The portion is displaced in the fabric width direction orthogonal to the sewing progress direction and is likely to deviate from a predetermined sewing position (stitch). Such a detachment is a fatal defect for a sewn product.
[0003]
As a device for optically detecting such a detachment and preventing the occurrence of defective sewing products, as disclosed in, for example, Japanese Utility Model Publication No. 59-25349, a light transmission type photoelectric sensor is used. There are known ones that are configured to detect detachment. The conventional detachment detection device disclosed in the above publications and the like is a light transmission device that includes a light projector that projects light onto a sewing fabric and a light receiver that receives light transmitted through the sewing fabric corresponding to the light projector. This type of sensor is designed to detect the sewn-off by detecting the increase or decrease of the amount of transmitted light that changes depending on whether the upper fabric and the lower fabric overlap, using the type photoelectric sensor. is there.
[0004]
[Problems to be solved by the invention]
However, in the case of a conventional detachment detection device using a light transmission type photoelectric sensor, the presence or absence of detachment is detected by increasing or decreasing the amount of transmitted light. Each time, it is necessary to perform troublesome and time-consuming work such as sensitivity adjustment (correction) of the photoelectric sensor, and there is a problem that it is not practical as a sewing machine slippage detection device used for sewing a small amount of various kinds of fabrics. there were.
[0005]
The present invention has been made in view of the above circumstances, and even when sewing any kind of fabric having different thicknesses and light transmission characteristics, it is possible to reliably and accurately prevent occurrence of detachment without requiring troublesome sensitivity adjustment work. An object of the present invention is to provide a sewing-separation detection device for a sewing machine that can detect the sewing machine.
[0006]
[Means for Solving the Problems]
In order to achieve the above-described object, a sewing-separation detecting device for a sewing machine according to the present invention is installed at a position near a needle drop portion in a needle plate, and the edge portions of the sewing fabric that are superposed on each other are set to a predetermined sewing position. A sewing-off detection device for a sewing machine configured to optically detect whether or not the position is off, The position in front of the sewing direction is longer than the knife mechanism that cuts the edges of the sewing fabric. Reflective photoelectric sensors that individually detect the presence or absence of the edge of the upper fabric and the edge of the lower fabric are provided at the upper and lower positions of the needle plate, and the projections from the upper and lower photoelectric sensors are provided. Reflecting parts are provided to reflect light rays upward and downward, respectively, and both detection signals from the upper and lower reflective photoelectric sensors are processed to determine whether or not the sewing fabric is dislodged. Detection means to operate In addition, of the upper and lower reflective photoelectric sensors, the lower photoelectric sensor is supported by the lower knife base of the knife mechanism, and the cut-and-cut is accompanied by the movement of the knife mechanism in the direction perpendicular to the sewing progress direction. When adjusting the position of the upper and lower reflective photoelectric sensors according to the adjustment of the position, the lower photoelectric sensor is adjusted with the lower knife base as the lower knife base moves to adjust the cut and cut position. Can be configured It is characterized by that.
[0007]
According to the present invention having the above-described configuration, the presence or absence of the edge portions of the upper and lower fabrics, which are superimposed one above the other, is individually determined by the reflective photoelectric sensors respectively provided above and below the needle plate. Since it is detected and the presence or absence of the sewing fabric is determined by signal processing of both detection signals, and the detection means operates based on the determination result, the thickness (thickness) of the sewing fabric and the light unique to the fabric When sewing any type of fabric with different transmission characteristics, the edge of either the upper fabric or the lower fabric is out of the predetermined sewing position without the troublesome sensitivity adjustment of the photoelectric sensor. It is possible to reliably and accurately detect detachment.
[0008]
Also, The upper and lower reflective photoelectric sensors are provided in front of the sewing mechanism with respect to the knife mechanism for trimming and cutting the edges of the sewing fabric, and the positions of the upper and lower reflective photoelectric sensors are set in a direction perpendicular to the sewing progress direction. By configuring it so that it can be adjusted according to the adjustment of the cut and cut position associated with the movement of the knife mechanism, both the upper and lower photoelectric sensors correspond to the cut and cut position of the knife mechanism as the overhang width is adjusted by moving the knife mechanism. It is possible to adjust the position to a predetermined detection position, and it is possible to reliably maintain a predetermined stitch-off detection function regardless of the adjustment of the overburden width.
[0009]
Moreover, Configuration for photoelectric sensor position adjustment and The lower side The photoelectric sensor is supported on the lower knife base of the knife mechanism, and the lower photoelectric sensor is configured so that the position of the lower photoelectric sensor can be adjusted integrally with the lower knife stage as the lower knife base moves to adjust the cut and cut position. Therefore, the amount of movement of the lower knife base, which is naturally performed for adjusting the overburden width, and the position adjustment amount of the lower photoelectric sensor can be completely matched. It is not necessary to adjust the position separately, and the overhang width can be changed easily and quickly while maintaining a predetermined detachment detection function.
The upper photoelectric sensor is positioned with the projected light beam from the lower photoelectric sensor adjusted in position as the lower knife base moves, so that the predetermined detection position after adjusting the overburden width is adjusted. Can be adjusted easily and accurately.
[0010]
Further, in the sewing-separation detecting device having the above-described configuration, a reflection portion that reflects the light beams projected from the upper and lower photoelectric sensors upward and downward, respectively. 2 Even if it is a thin fabric, by adopting the configuration formed on the upper and lower surfaces of the sewing fabric guide members that are interposed between the upper and lower fabrics and guide the movement of the upper and lower fabrics in the sewing progress direction, as described in The upper and lower fabrics are guided along the guide member so as not to loosen, and the upper and lower photoelectric sensors are used to check the presence or absence of the edge of the fabric while ensuring the upward and downward reflection of the projected light beam. Detection performance can be improved.
[0011]
In the sewing-separation detection device of a sewing machine provided with the guide member with the vertical reflection surface as described above, 3 Even if the sewing target object is a cylindrical sewing object, the guide member is configured to be freely changeable between the sewing material guiding action position and the non-guide action position spaced from the needle plate. The guide member does not obstruct the predetermined sewing and does not obstruct the removal of the sewn product after the sewing. That is, when the sewing of the tubular sewing product proceeds and the sewing start end portion comes before the needle drop portion, the guide member is moved to the non-guide operation position (retracted) so that the sewing start end portion becomes the guide member. It is possible to reliably sew to the end of the sewing without being caught by the sewing machine, and it is possible to take out the tubular sewn product after sewing from the sewing location without being obstructed by the guide member.
[0012]
Furthermore, in the sewing-separation detection device of the sewing machine configured as described above, 4 As described above, the upper and lower photoelectric sensors have polarizing filters on the front surface of the light projecting and receiving elements, respectively, and on the light projecting side, only the light beams in the horizontal or vertical direction are projected through the polarizing filter. The light receiving side uses a retro-reflective photoelectric sensor that passes through a polarizing filter and receives only reflected light in the vertical or horizontal direction on the light receiving side, and projects light beams from these upper and lower photoelectric sensors. As a reflection surface of the reflection part to be reflected upward and downward, a retroreflective tape having a function of polarizing and reflecting the light beam of only the horizontal or vertical wave to be projected to the wave beam of any direction. By using it, even if there is a shiny object or part at the projection position, or even if the fabric itself is highly light reflective, the reflected light (disturbance light) from them and the reflection tape It is possible to distinguish clearly from the incident light, so that the upper and lower photoelectric sensors accurately detect only the presence or absence of the edges of the upper and lower fabrics, eliminating false detection and false detection operations, and the specified sewing detection accuracy Can be significantly increased.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic perspective view of a main part of an overlock sewing machine M provided with a sewing-off detecting device according to the present invention, and FIG. 2 is a plan view of the main part of the sewing machine M. A needle plate 2 is fixed to the cross plate 1 of the overlock sewing machine M so that the upper surface thereof is flush with the upper surface of the cross plate 1. A needle drop portion of a sewing needle (not shown) attached to a lower end portion of a needle bar 4 supported by the sewing machine frame 3 so as to be capable of reciprocating vertically in the lower portion of the needle plate 2 via a needle stopper 5. At the front and rear positions across 6, there are disposed feed dogs before and after feeding the sewing fabric W overlapped in the vertical direction in the sewing progress direction indicated by the arrow Y (not shown because it is well known). In addition, a presser foot 7 that presses the fabric to be sewn W against the upper surface of the needle plate 2 is provided on the upper portion of the needle plate 2 so as to be movable up and down via a presser arm 8. While feeding in the sewing progress direction Y, the edge stitching is performed by the cooperative action of the sewing needle and a looper (not shown).
[0014]
The sewing fabric W to be fed in the sewing progress direction Y toward the needle drop portion 6 along the upper surfaces of the cross plate 1 and the needle plate 2 at a position before the needle drop portion 6 in the needle plate 2 in the sewing progress direction Y. A knife mechanism 9 for cutting and trimming the end edge We is provided. The knife mechanism 9 includes a flat upper knife 9A and a belt-like lower knife 9B, and the cut and cut position is obtained by moving the knife mechanism 9 in the X1-X2 direction orthogonal to the sewing progress direction Y. That is, the overhang width is configured to be adjustable. The specific configuration of the knife mechanism 9 and the adjustment structure of the overburden width are as follows.
[0015]
That is, as clearly shown in FIG. 5, an L-shaped upper knife is fixed to the upper knife shaft arm 11 which is fixed to and swings on the upper knife shaft 10 interlocked with the main shaft of the overlock sewing machine (not shown for illustration). A holder 12 is attached through a set screw 13 and a long hole 14 so as to be movable and fixed in the direction of the arrow X1-X2. The holder 12 is pressed against the side of the upper female holder 12 and vertically moved through a bolt 15 and a long hole 16. A plate-shaped upper knife 9A is attached so that the position can be adjusted.
[0016]
On the other hand, the lower knife base mounting base 17 arranged and fixed at the lower part of the cross plate 1 has an upper knife in the X1-X2 direction orthogonal to the sewing progress direction Y via a spring 18 incorporated in the mounting base 17. The lower knife base 19 is supported in a state of being elastically biased toward the 9A side, and the lower knife base 9B is fixedly held on the lower knife base 19 via the lower knife presser 20 and the set screw 21. A set screw 22 is provided that can fix the lower knife base 19 to the lower knife mounting base 17 against the elastic biasing force of the spring 18. In FIG. 5, reference numeral 23 denotes a detent member for the lower knife base 19, which is fixed to the lower knife mounting base 17 via a set screw 24.
[0017]
In the knife mechanism 9 configured as described above, the set screw 13 is loosened, and the upper knife holder 12 and the upper knife 9A are moved and fixed along the long hole 14 by a necessary amount in the X1-X2 direction perpendicular to the sewing progress direction Y. At the same time, the set screw 22 is loosened and the lower knife base 19 and the lower knife 9B are moved in the same X1-X2 direction by the biasing force of the spring 18 or against the biasing force of the spring 18 to move both the upper and lower knife 9A. , 9B is elastically brought into close contact with each other so that the overburden width can be adjusted.
[0018]
As shown clearly in FIGS. 3 and 4, the upper fabric Wu and the lower fabric Wd are respectively disposed at the upper and lower positions of the needle plate 2 in the front position in the sewing progress direction Y with respect to the knife mechanism 9 as described above. Reflective photoelectric sensors 25 and 26 that individually detect the presence or absence of the edge portions of the upper fabric Wu and the lower fabric Wd are provided depending on whether or not the reflected light of the light beams projected toward each other is received. Of these upper and lower reflective photoelectric sensors 25, 26, the lower photoelectric sensor 26 includes a female mechanism component such as the lower knife base 19 of the female mechanism 9 described above, and there is no room for installation space. , Using fiber sensor.
[0019]
As shown in FIG. 1, the upper reflective photoelectric sensor 25 has an X1 orthogonal to the sewing progress direction Y through a long hole 28 formed in the sensor mounting arm plate 27 and a bolt 29 fitted thereto. It is attached to the sewing machine frame 3 so as to be movable and fixed in the −X2 direction, and is configured such that the sensing position can be adjusted in accordance with the adjustment of the cut and cut position (overhead width) of the knife mechanism 9.
[0020]
On the other hand, the lower photoelectric sensor 26 composed of a fiber sensor is fixedly supported on the lower knife base 19 in the knife mechanism 9 via a fiber support 30 and a fiber presser 31 as shown in FIGS. Thus, the sensing position can be adjusted integrally with the lower knife 9B and the lower knife table 19 in accordance with the movement of the lower knife table 19 in the X1-X2 direction for adjusting the overburden width described above. In addition, when the photoelectric sensor 26 is moved to any position in the X1-X2 direction integrally with the lower knife base 19 for adjusting the overburden width at the needle plate 2 portion where the detection end 26a of the lower photoelectric sensor 26 faces. However, a long-hole-shaped guide groove 32 is formed so that a predetermined sensing function for the lower fabric Wd can be maintained.
[0021]
Further, between the upper fabric Wu and the lower fabric Wd, there is interposed a plate-shaped sewing fabric guide member 33 for guiding the movement of the lower fabrics Wu, Wd in the sewing progress direction Y. Reflex reflection tapes 34 and 35 are respectively attached to the upper and lower surfaces of 33 to form reflection surfaces (reflecting portions) for reflecting the projected light beams from the upper and lower photoelectric sensors 25 and 26 upward and downward.
[0022]
The guide member 33 with the upper and lower reflection tapes 34 and 35 is fixed to the distal end portion of a movable rod 38a of an expansion / contraction (advance / retreat) cylinder 38 fixedly supported on the sewing machine frame 3 via a mounting plate 36 and a base 37. 38 is configured so that the position thereof can be freely changed between a sewing cloth guiding action position extending on the needle plate 2 and a non-guiding action position spaced from the needle plate 2 by the expansion and contraction operation of the needle 38.
[0023]
FIG. 6 is a block diagram showing a circuit configuration of the detachment detecting device including the upper and lower reflective photoelectric sensors 25 and 26. The detection signals S1 and S2 from the upper and lower photoelectric sensors 25 and 26 are amplified by amplifiers 40 and 41, respectively. After that, it is input to the control unit 42. In addition to the detection signals S1 and S2, the control unit 42 includes a detection signal S3 from a rotation detector 44 that is attached to, for example, a main shaft (not shown) of the overlock sewing machine M and detects the presence or absence of rotation, and sewing progress. An allowable sewing amount (number of needle movements) setting signal S4 is input from an allowable sewing amount setting device 43 that inputs the number of stitches as an allowable sewing amount within a certain length range in the direction Y in advance by an operator. The control unit 42 compares the number of movements corresponding to the input continuation time of one of the detection signals S1 and S2 from the upper and lower photoelectric sensors 25 and 26 with the allowable number of movements of the setting signal S4. When the detected number of movements exceeds the allowable number of movements, it is determined that there is a sewing failure and a signal S5 is output.
[0024]
The control unit 42 is connected to a sewing-off notification means 45 comprising at least one of a lamp, a buzzer, or a display screen. The control unit 42 receives an output signal S5 from the control unit 42 and performs lighting, ringing or display operation. The operator is configured to inform the operator that the disengagement has occurred. The permissible amount of stitching can be arbitrarily changed by setting the number of stitches. Instead of this number of stitches, either one of the detection signals S1, S2 from the photoelectric sensors 25, 26 is controlled by the control unit 42. It is also possible to use a timer that starts its operation from the time it is input to, and make the allowable amount of detachment variable by setting the operation time limit of this timer.
[0025]
Next, with reference to the flowchart shown in FIG. 7 and FIG. 8 (FIG. 8), for example, an overlock detection operation when performing over-sleeve sewing of a T-shirt using the overlock sewing machine M having the above-described configuration of the overlock sewing device. This will be briefly described with reference to the operation diagrams of A) and (B).
[0026]
The sewing fabric W in which the upper fabric Wu and the lower fabric Wd are vertically overlapped, such as a T-shirt sleeve fabric and a garment fabric, is the upper surface of the cross plate 1 and the needle plate 2 by the front and rear feed teeth. , The edge We of the knife mechanism 9 is cut and aligned by a knife mechanism 9 at a position before the needle drop portion 6, and then sent to the needle drop portion 6, and the looper not shown in the drawing. Edge sewing is performed by the cooperative action.
[0027]
At the time of edge stitching as described above, the guide member 33 with the upper and lower reflection tapes 34 and 35 is positioned at the sewing fabric guide operation position with its tip extending on the needle plate 2 via the cylinder 38, and sewing is performed. Even if the fabric W is thin, the upper and lower fabrics Wu and Wd are guided to move along the guide member 33 so as not to be loosened. Then, pulsed light beams are projected from the upper and lower reflective photoelectric sensors 25 and 26 to the edge portions of the upper and lower fabrics Wu and Wd of the sewing fabric W at a position before the knife mechanism 9, and the reflected light thereof. The presence / absence of the edge portions of the upper and lower fabrics Wu and Wd is detected depending on whether or not light is received (steps S11 and S12).
[0028]
Here, the upper and lower photoelectric sensors 25 and 26 receive the reflected light when both the edge portions of the upper fabric Wu and the lower fabric Wd protrude to the right of the projected light as shown in FIG. 8A. However, since the detection signals S1 and S2 with the fabric edge are input from the photoelectric sensors 25 and 26 to the control unit 42, the control unit to which the detection signals S1 and S2 with the fabric edge are input. In 42, it is determined that there is no detachment by signal processing of these detection signals S1 and S2 (step S13), and the predetermined edge stitching is continued without proceeding to the next step.
[0029]
On the other hand, as shown in FIG. 8B, in the state where either one of the upper fabric Wu and the lower fabric Wd, for example, the edge of the upper fabric Wu is shifted to the left side from the projection light beam. The projected light beam from the upper photoelectric sensor 25 is reflected upward from the reflective tape 34 bonded to the upper surface of the guide member 33, and the upper photoelectric sensor 25 receives the reflected light. A detection signal S1 having no fabric edge is input from the photoelectric sensor 25 to the control unit 42, and a detection signal S2 having a fabric edge is input from the lower photoelectric sensor 26 to the control unit 42. It is determined that there is a detachment by the signal processing of S1 and S2 (step S13).
[0030]
The control unit 42 is input with a stitch number setting signal S4 as an allowable amount of stitching off along the sewing progress direction Y, which has been previously input by the operator into the allowable stitching setter 43. The allowable number of movements M1 of the setting signal S4 and the detected number of movements M2 corresponding to the input duration of the detection signal S1 (or S2) are compared (step S14), and when the detected number of movements M2 is smaller than the allowable number of movements M1, The signal S5 is not output, and when the detected number of stitches M2 exceeds the allowable number of stitches M1, it is determined that the disengagement has occurred, and the signal S5 is output from the control unit 42 (step S15). When the output signal S5 from the control unit 42 is input to the sewing-off notification means 45, the lamp is turned on or the buzzer sounds to notify the operator of the occurrence of sewing-off.
[0031]
As described above, the presence or absence of the edge portions of the upper fabric Wu and the lower fabric Wd, which are superimposed one above the other, are reflected by the reflective photoelectric sensors 25 and 26 respectively provided above and below the needle plate 2. By individually detecting and determining whether or not the sewing fabric W is dislodged by signal processing of both detection signals, and operating the leaving means 44 based on the determination result, the thickness (thickness) of the sewing fabric W or When sewing any kind of fabric having different light transmission characteristics peculiar to the fabric, it is not necessary to adjust the sensitivity of the photoelectric sensors 25 and 26, and either the upper fabric Wu or the lower fabric Wd has an edge portion thereof. If a detachment occurs that deviates from a predetermined sewing position, it can be reliably and accurately detected.
[0032]
As in the present embodiment, the lower photoelectric sensor 26 is supported on the lower knife base 19 of the knife mechanism 9, and the lower photoelectric sensor 19 is moved along with the movement of the lower knife stage 19 for adjusting the cut and cut position. Necessary for the amount of movement of the lower knife table 19 and the adjustment of the overburden width, which is naturally performed for adjusting the overburden width, by configuring the sensor 26 so as to be adjustable in the X1-X2 direction integrally with the lower knife base 19. It is possible to completely match the position adjustment amount of the lower photoelectric sensor 26 to be a predetermined amount of sewing without adjusting the position of the lower photoelectric sensor 26 separately after adjusting the overburden width. Overhead width adjustment can be performed easily and quickly while ensuring the detection function. Here, the upper photoelectric sensor 25 is formed on the sensor mounting arm plate 27 with the projection light beam from the lower photoelectric sensor 26 adjusted in position integrally with the movement of the lower knife base 19 as a sight. By adjusting the sensing position by moving and fixing in the X1-X2 direction orthogonal to the sewing progress direction Y through the hole 28 and the bolt 29 fitted to the hole 28, the predetermined detection position after adjusting the overburden width can be easily and accurately. Can be adjusted.
[0033]
Moreover, the sewing target object is a cylindrical sewing object by configuring the guide member 33 so that the position can be freely changed between the sewing cloth guiding action position as described above and the non-guiding action position spaced from the needle plate 2. Even in this case, when the sewing of the cylindrical sewing product progresses and the sewing start end portion comes before the needle drop portion 6, the position of the guide member 33 is changed (retracted) to the non-guide operation position via the cylinder 38. Thus, the sewing start end can be reliably sewed to the sewing end without being caught by the guide member 33, and the cylindrical sewing product after sewing can be easily made from the sewing location without being obstructed by the guide member 33. Can be taken out.
[0034]
Further, as the upper and lower photoelectric sensors 25 and 26, a polarizing filter (not shown) is provided on the front surface of the light projecting / receiving element, respectively, and the light projecting side is passed through the polarizing filter in the horizontal direction (or vertical direction). A retro-reflective photoelectric sensor that projects only the wave rays and receives only the reflected rays of the vertical (or horizontal) waves through the polarizing filter on the light receiving side is used. As the retroreflective tapes 34 and 35 for reflecting the projected light beams from the photoelectric sensors 25 and 26 upward and downward, the light beams only in the horizontal direction (or vertical direction) to be projected are waves in all directions. By using a retroreflective tape that has the function of polarizing and reflecting the light beam, there is a glossy object or part at the light projection position, or the sewing fabric W itself is highly light reflective. Even if it exists, it is possible to distinguish clearly the reflected light (disturbance light) from them, and the reflected light from the reflective tapes 34 and 35, and, thereby, the upper and lower photoelectric sensors 25 and 26 are the upper and lower fabrics Wu and Wd. Only the presence / absence of the edge portion is accurately detected, and erroneous detection and erroneous detection operations are eliminated, so that the predetermined accuracy of detection of detachment can be significantly increased.
[0035]
The reflecting portion in the present invention is most preferably formed by the above-described retroreflective tapes 34 and 35 having a polarizing function. However, even when a reflecting tape having no polarizing function is used, the guide member 33 is also used. The upper and lower surfaces may be mirror-finished to form a reflecting surface.
[0036]
In addition, the present invention basically only requires that the operator recognizes that the sewing has been dislodged, thereby preventing the occurrence of defective sewing products. Therefore, the notification means 44 such as a lamp, a buzzer, or a display screen is provided. Although what was provided was demonstrated, you may add the structure which stops automatically the operation | movement of the sewing machine M in addition to this in connection with detection of detachment.
[0037]
【The invention's effect】
As described above, according to the present invention, the presence or absence of the edge portions of the upper fabric and the lower fabric that are superposed on each other is individually detected, and the presence or absence of the sewing fabric being sewn off by signal processing of both detection signals. Since the detection means is operated based on the determination result, a troublesome photoelectric sensor can be used when sewing any kind of fabric having different thickness (thickness) of the sewing fabric or light transmission characteristics peculiar to the fabric. This makes it possible to reliably and accurately detect the occurrence of sewing disengagement in which the edge of either the upper fabric or the lower fabric deviates from the predetermined sewing position. Play.
[0038]
Also , Female It is possible to adjust the position of the upper and lower photoelectric sensors to a predetermined detection position corresponding to the cut-and-cut position of the knife mechanism in accordance with the adjustment of the overburden width due to the movement of the mechanism. The sewing detection function can be reliably maintained.
[0039]
Besides, overburden The amount of movement of the lower knife base, which is naturally performed for width adjustment, and the position adjustment amount of the lower photoelectric sensor can be perfectly matched.After adjusting the overburden width, the position of the lower photoelectric sensor can be adjusted. It is possible to easily and quickly adjust the overburden width while securing a predetermined stitch-off detection function without requiring separate adjustment.
[0040]
Claims 2 According to the invention described above, in addition to the above-described effect, even when the fabric is thin, the upper and lower fabrics are projected along the guide member so that the upper and lower fabrics do not loosen and the like. It is possible to improve the detection performance of the presence / absence of the fabric edge by the upper and lower photoelectric sensors by ensuring the light reflecting effect.
[0041]
And claims 3 According to the invention described in the above, in addition to the above-described effects, even in the case of a tubular sewn product, the guide member may interfere with predetermined sewing, or may interfere with the removal of the sewn product after sewing. In addition, the sewn-off detection device can be effectively applied to a tubular sewn product.
[0042]
Furthermore, the claims 4 According to the invention described in (2), it is possible to clearly distinguish between disturbance light and regular reflected light, thereby eliminating the erroneous detection and erroneous detection operations and significantly increasing the predetermined stitch-off detection accuracy. Can do.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view of a main part of an overlock sewing machine provided with a detachment detecting device according to the present invention.
FIG. 2 is a plan view of a main part of the sewing machine.
FIG. 3 is a front view of an essential part of the sewing machine.
FIG. 4 is a right side view of the main part of the sewing machine.
FIG. 5 is an exploded perspective view of a main part showing a detailed configuration of a knife mechanism in the sewing machine.
FIG. 6 is a block diagram showing a circuit configuration of a detachment detection device including upper and lower reflective photoelectric sensors.
FIG. 7 is a flowchart for explaining an operation of detecting a detachment during overlock sewing.
FIGS. 8A and 8B are schematic side views for explaining the state of detection of the edge portions of the upper and lower fabrics during over stitching.
[Explanation of symbols]
2 Needle plate
6 Needle drop
9 Female mechanism
9A Upper knife
9B Lower knife
19 Lower knife stand
25, 26 Reflective photoelectric sensor
33 Sewing material guide member
34, 35 Retroreflective tape
45 Non-sewing notification means
M Overlock sewing machine
W Sewing fabric
Wu top fabric
Wd under fabric
S1, S2 Photoelectric sensor detection signal
Y Sewing direction
X1-X2 Overhead width adjustment direction

Claims

A sewing machine that is installed in the vicinity of the needle drop portion of the throat plate and configured to optically detect whether or not the edge of the sewing fabric that is superposed vertically deviates from a predetermined sewing position. A disengagement detecting device,
The presence or absence of the edge of the upper fabric and the edge of the lower fabric individually on the upper and lower positions of the needle plate in the front of the sewing progressing direction relative to the knife mechanism that trims and cuts the edge of the sewing fabric. A reflective photoelectric sensor to detect is provided,
Reflecting portions are provided to reflect the projected light beams from the upper and lower photoelectric sensors upward and downward, respectively.
And processes the two detection signals produced reflection photoelectric sensor vertically to determine the sewing whether out of sewing fabric, is provided et been detected device operated in accordance with the determination result,
Further, of the upper and lower reflective photoelectric sensors, the lower photoelectric sensor is supported by the lower knife base of the knife mechanism, and the position of the cut-and-cut position associated with the movement of the knife mechanism in the direction orthogonal to the sewing progress direction. When adjusting the position of the upper and lower reflective photoelectric sensors according to the adjustment, the lower photoelectric sensor can be adjusted with the lower knife base as the lower knife base moves to adjust the cut and cut position. A sewing-off detection device for a sewing machine, characterized in that it is configured .

2. The sewing-separation detection device for a sewing machine according to claim 1, wherein the reflection portions are formed on upper and lower surfaces of a sewing fabric guide member that is interposed between the upper and lower fabrics and guides the movement of the upper and lower fabrics in the sewing progress direction.

The sewing cloth guide member reflecting portion is formed on the upper and lower surfaces, according to claim 2 in which the position change is freely configured over between the non-guiding action position spaced from the sewing cloth guiding action position and the needle plate Sewing machine slippage detection device.

As the upper and lower photoelectric sensors, each has a polarizing filter on the front surface of the light projecting / receiving element, and on the light projecting side, only the light beam in the horizontal or vertical direction is projected through the polarizing filter, and On the light-receiving side, a retro-reflective photoelectric sensor that passes through a polarizing filter and receives only reflected light in the vertical or horizontal direction is used, and the projected light from these upper and lower photoelectric sensors is directed upward and downward. As the reflecting surface of the reflecting part to be reflected, a retroreflective tape having a function of polarizing and reflecting only the light beam in the horizontal or vertical direction to be reflected to the light beam in any direction is used. The sewing-separation detection device for a sewing machine according to any one of claims 1 to 3 .